Interface of a strus IR storage. More...

#include <storageClientInterface.hpp>

Public Types
enum	DocumentStatisticsType { StatNofTerms = 1, StatNofTermOccurrencies = 2 }
	Enumeration of document statistics. More...

Public Member Functions
virtual	~StorageClientInterface ()
	Destructor. More...

virtual std::string	config () const =0
	Get the interpreted configuration this storage client was created with. More...

virtual PostingIteratorInterface *	createTermPostingIterator (const std::string &type, const std::string &value, const Index &length) const =0
	Create an iterator on the occurrencies of a term in the storage. More...

virtual StructIteratorInterface *	createStructIterator (const std::string &structstr) const =0
	Create an iterator on the structures (relations of ordinal position ranges) of a defined type. More...

virtual PostingIteratorInterface *	createBrowsePostingIterator (const MetaDataRestrictionInterface *restriction, const Index &maxpos) const =0
	Create an iterator on all enumerable postings of document selected by a metadata restriction. More...

virtual PostingIteratorInterface *	createFieldPostingIterator (const std::string &meta_fieldStart, const std::string &meta_fieldEnd) const =0
	Create an iterator postings specified as field in the meta data (by start and end position) More...

virtual ForwardIteratorInterface *	createForwardIterator (const std::string &type) const =0
	Create a viewer to inspect the term stored values with the forward index of the storage. More...

virtual DocumentTermIteratorInterface *	createDocumentTermIterator (const std::string &type) const =0
	Create an iterator on term occurrencies in documents (support for feature selection) More...

virtual InvAclIteratorInterface *	createInvAclIterator (const std::string &username) const =0
	Create a an iterator on the numbers of documents a specified user is allowed to see. More...

virtual AclReaderInterface *	createAclReader () const =0
	Create a an iterator on the access control lists of documents. More...

virtual Index	nofDocumentsInserted () const =0
	Get the number of documents inserted in this storage instance. More...

virtual Index	documentFrequency (const std::string &type, const std::string &term) const =0
	Get the local document frequency of a feature in this storage instance. More...

virtual Index	maxDocumentNumber () const =0
	Get the highest document number used in this stogage. More...

virtual Index	documentNumber (const std::string &docid) const =0
	Get the local internal document number. More...

virtual Index	termTypeNumber (const std::string &type) const =0
	Get the local internal term type number. More...

virtual bool	isForwardIndexTerm (const std::string &type) const =0
	Evaluate if there exists forward index blocks for this type. More...

virtual ValueIteratorInterface *	createTermTypeIterator () const =0
	Create an iterator on the term types inserted. More...

virtual ValueIteratorInterface *	createStructTypeIterator () const =0
	Create an iterator on the structure types inserted. More...

virtual ValueIteratorInterface *	createTermValueIterator () const =0
	Create an iterator on the term value inserted. More...

virtual ValueIteratorInterface *	createDocIdIterator () const =0
	Create an iterator on the document identifiers inserted. More...

virtual ValueIteratorInterface *	createUserNameIterator () const =0
	Create an iterator on the user names used in document access restrictions. More...

virtual Index	documentStatistics (const Index &docno, const DocumentStatisticsType &stat, const std::string &type) const =0
	Get one specified element of the documents statistics for a term type on the local server node. More...

virtual MetaDataReaderInterface *	createMetaDataReader () const =0
	Create an interface to access items of document metadata. More...

virtual MetaDataRestrictionInterface *	createMetaDataRestriction () const =0
	Create an object for restrictions on metadata. More...

virtual AttributeReaderInterface *	createAttributeReader () const =0
	Create an interface to access attributes attached to documents for representation. More...

virtual StorageTransactionInterface *	createTransaction ()=0
	Create an insert/update transaction object. More...

virtual StatisticsIteratorInterface *	createAllStatisticsIterator (bool sign=true)=0
	Creates an iterator on storage statistics messages for initialization/deregistration. More...

virtual StatisticsIteratorInterface *	createChangeStatisticsIterator ()=0
	Creates an iterator on the storage statistics messages created by updates of this storage. More...

virtual const StatisticsProcessorInterface *	getStatisticsProcessor () const =0
	Get the processing message interface for introspecting and packing messages outside the queue context. More...

virtual StorageDocumentInterface *	createDocumentChecker (const std::string &docid, const std::string &logfilename) const =0
	Create an interface to verify, if the contents of a document are inserted correctly into the storage. The checking is invoked by calling the StorageDocumentInterface::done() method after the definition of all elements. More...

virtual bool	checkStorage (std::ostream &errorlog) const =0
	Iterate through all key/value pairs and check their data for validity. More...

virtual void	close ()=0
	Close client connection and eventually do some cleanup. More...

Detailed Description

Interface of a strus IR storage.

Member Enumeration Documentation

enum strus::StorageClientInterface::DocumentStatisticsType

Enumeration of document statistics.

Enumerator
StatNofTerms	number of distinct terms
StatNofTermOccurrencies	number of accumulated dfs (number of terms)

Constructor & Destructor Documentation

virtual strus::StorageClientInterface::~StorageClientInterface ( )

inlinevirtual

Destructor.

Remarks: Should call call 'close()' but ignore errors there silently

Member Function Documentation

virtual bool strus::StorageClientInterface::checkStorage ( std::ostream & errorlog ) const

pure virtual

Iterate through all key/value pairs and check their data for validity.

Parameters

[out] errorlog stream for reporting errors

Returns: true, if the check succeeds, false if it fails

virtual void strus::StorageClientInterface::close ( )

pure virtual

Close client connection and eventually do some cleanup.

Remarks: This method is not implicitely called with the destructor because it might be a complicated operation that cannot be afforded in panic shutdown.

Note: the method does not have to be called necessarily; it calls compactDatabase of the underlying database and can therefore last some time (some minutes in case of leveldb after large inserts).

virtual std::string strus::StorageClientInterface::config ( ) const

pure virtual

Get the interpreted configuration this storage client was created with.

Returns: the configuration as string

virtual AclReaderInterface* strus::StorageClientInterface::createAclReader ( ) const

pure virtual

Create a an iterator on the access control lists of documents.

Returns: the iterator on the ACLs

Note: The storage has to be created with access control enabled

virtual StatisticsIteratorInterface* strus::StorageClientInterface::createAllStatisticsIterator ( bool sign = true )

pure virtual

Creates an iterator on storage statistics messages for initialization/deregistration.

Parameters

[in] sign true = positive, false = negative, means all offsets are inverted and isnew is false too (used for deregistration)

Returns: the iterator on the statistics message blobs

virtual AttributeReaderInterface* strus::StorageClientInterface::createAttributeReader ( ) const

pure virtual

Create an interface to access attributes attached to documents for representation.

Returns: the interface to access document attributes (with ownership)

virtual PostingIteratorInterface* strus::StorageClientInterface::createBrowsePostingIterator	(	const MetaDataRestrictionInterface *	restriction,
		const Index &	maxpos
	)		const

pure virtual

Create an iterator on all enumerable postings of document selected by a metadata restriction.

Parameters

[in]	restriction	restriction on metadata that have to be fulfilled by the documents referenced in the result posting sets.
[in]	maxpos	maximum position visited.

Returns: the created iterator reference (with ownership)

Note: This iterator use is mainly for browsing occurrencies fulfilling a condition without query involved

Remarks: The iterator does not take the alive status of the documents into account. You have to formulate a restriction expression that does not match deleted documents if you do not want deleted documents in your iterated set of postings.; The iterator does not take the document length into account. It returns the set of postings with positions in the range [1..maxpos]. Read postings you get only when joining this set with another.

virtual StatisticsIteratorInterface* strus::StorageClientInterface::createChangeStatisticsIterator ( )

pure virtual

Creates an iterator on the storage statistics messages created by updates of this storage.

Returns: the iterator on the statistics message blobs

virtual ValueIteratorInterface* strus::StorageClientInterface::createDocIdIterator ( ) const

pure virtual

Create an iterator on the document identifiers inserted.

Returns: the iterator

virtual StorageDocumentInterface* strus::StorageClientInterface::createDocumentChecker	(	const std::string &	docid,
		const std::string &	logfilename
	)		const

pure virtual

Create an interface to verify, if the contents of a document are inserted correctly into the storage. The checking is invoked by calling the StorageDocumentInterface::done() method after the definition of all elements.

Parameters

[in]	docid	identifier (URI) of the document to check
[in]	logfilename	Where to log checking failures ("-" for stdout)

Returns: the created document interface (with ownership)

virtual DocumentTermIteratorInterface* strus::StorageClientInterface::createDocumentTermIterator ( const std::string & type ) const

pure virtual

Create an iterator on term occurrencies in documents (support for feature selection)

Parameters

[in] type type name of the term

Returns: the created iterator reference (with ownership)

virtual PostingIteratorInterface* strus::StorageClientInterface::createFieldPostingIterator	(	const std::string &	meta_fieldStart,
		const std::string &	meta_fieldEnd
	)		const

pure virtual

Create an iterator postings specified as field in the meta data (by start and end position)

Parameters

[in]	meta_fieldStart	meta data element that specifies the start of the field
[in]	meta_fieldEnd	meta data element that specifies the end of the field (first position not belonging to the field anymore)

Returns: the created iterator reference (with ownership)

Note: Fields can avoid superfluos access on posting blocks; Fields give you the possibility to treat elements in the document differently while using the same statistics that are defined by feature type

virtual ForwardIteratorInterface* strus::StorageClientInterface::createForwardIterator ( const std::string & type ) const

pure virtual

Create a viewer to inspect the term stored values with the forward index of the storage.

Parameters

[in] type type name of the term to be inspected

Returns: the created viewer reference to be disposed with delete

virtual InvAclIteratorInterface* strus::StorageClientInterface::createInvAclIterator ( const std::string & username ) const

pure virtual

Create a an iterator on the numbers of documents a specified user is allowed to see.

Parameters

[in] username name of the user

Returns: the iterator on the documents (with ownership) or NULL, if there is no access control enabled

Note: The storage has to be created with access control enabled

virtual MetaDataReaderInterface* strus::StorageClientInterface::createMetaDataReader ( ) const

pure virtual

Create an interface to access items of document metadata.

Returns: the interface to access document metadata (with ownership)

virtual MetaDataRestrictionInterface* strus::StorageClientInterface::createMetaDataRestriction ( ) const

pure virtual

Create an object for restrictions on metadata.

Returns: the created, uninitialized restriction object

virtual StructIteratorInterface* strus::StorageClientInterface::createStructIterator ( const std::string & structstr ) const

pure virtual

Create an iterator on the structures (relations of ordinal position ranges) of a defined type.

Parameters

[in] structstr name of the structure to get the iterator on

Returns: the created iterator reference (with ownership)

virtual ValueIteratorInterface* strus::StorageClientInterface::createStructTypeIterator ( ) const

pure virtual

Create an iterator on the structure types inserted.

Returns: the iterator

virtual PostingIteratorInterface* strus::StorageClientInterface::createTermPostingIterator	(	const std::string &	type,
		const std::string &	value,
		const Index &	length
	)		const

pure virtual

Create an iterator on the occurrencies of a term in the storage.

Parameters

[in]	type	type name of the term
[in]	value	value string of the term
[in]	length	ordinal position length assigned to the term (may differ from 1 for terms representing multipart patterns)

Remarks: the length is considered as an attribute and not used in set operations for joining posting sets. It is used as hint only in some summarization and weighting functions for handling multi-word phrases correctly.

Returns: the created iterator reference (with ownership)

virtual ValueIteratorInterface* strus::StorageClientInterface::createTermTypeIterator ( ) const

pure virtual

Create an iterator on the term types inserted.

Returns: the iterator

virtual ValueIteratorInterface* strus::StorageClientInterface::createTermValueIterator ( ) const

pure virtual

Create an iterator on the term value inserted.

Returns: the iterator

virtual StorageTransactionInterface* strus::StorageClientInterface::createTransaction ( )

pure virtual

Create an insert/update transaction object.

Returns: the created transaction interface (with ownership)

Note: this function is thread safe, multiple concurrent transactions are allowed

virtual ValueIteratorInterface* strus::StorageClientInterface::createUserNameIterator ( ) const

pure virtual

Create an iterator on the user names used in document access restrictions.

Returns: the iterator

virtual Index strus::StorageClientInterface::documentFrequency	(	const std::string &	type,
		const std::string &	term
	)		const

pure virtual

Get the local document frequency of a feature in this storage instance.

Parameters

[in]	type	the term type addressed
[in]	term	the term value addressed

Returns: the local document frequency

virtual Index strus::StorageClientInterface::documentNumber ( const std::string & docid ) const

pure virtual

Get the local internal document number.

Parameters

[in] docid document id of the document inserted

Returns: the document number or 0, if it does not exist

virtual Index strus::StorageClientInterface::documentStatistics	(	const Index &	docno,
		const DocumentStatisticsType &	stat,
		const std::string &	type
	)		const

pure virtual

Get one specified element of the documents statistics for a term type on the local server node.

Parameters

[in]	docno	the local internal document number addressed (return value of documentNumber( const std::string&) const)
[in]	stat	the enumeration value of the statistics to get
[in]	type	the term type addressed

virtual const StatisticsProcessorInterface* strus::StorageClientInterface::getStatisticsProcessor ( ) const

pure virtual

Get the processing message interface for introspecting and packing messages outside the queue context.

Returns: the message processor interface

virtual bool strus::StorageClientInterface::isForwardIndexTerm ( const std::string & type ) const

pure virtual

Evaluate if there exists forward index blocks for this type.

Parameters

[in] type term type name

Returns: true, if yes, false if no or if an error occurred (check error)

virtual Index strus::StorageClientInterface::maxDocumentNumber ( ) const

pure virtual

Get the highest document number used in this stogage.

Returns: the document number, or 0, if no documents are inserted

virtual Index strus::StorageClientInterface::nofDocumentsInserted ( ) const

pure virtual

Get the number of documents inserted in this storage instance.

Returns: the number of documents

virtual Index strus::StorageClientInterface::termTypeNumber ( const std::string & type ) const

pure virtual

Get the local internal term type number.

Parameters

[in] type term type name

Returns: the term type number or 0, if it is not known yet

The documentation for this class was generated from the following file:

/home/patrick/Projects/github/strus/include/strus/storageClientInterface.hpp

Public Types

Public Member Functions

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation